1. Field of the Invention
This invention pertains generally, though not exclusively, to paint ball guns used for recreational and training purposes. For the purposes of this disclosure, paint ball guns are specifically defined as apparatus that propel paint capsules from a barrel in rapid succession and at relatively high speeds. The paint ball capsules are designed to break upon impact with an object or person, thereby rendering an identifiable mark without injuring the person or object. The present invention more specifically pertains to an electronically controlled magazine that stores and feeds paint balls into a firing chamber.
2. Description of the Related Art
Paint ball guns can fire in rapid succession a relatively large number of paint balls in a short period of time. A magazine stores the paint balls until the balls are delivered to the gun firing chamber. The guns use compressed gas as the propellant, and are usually triggered by a user squeezing a conventionally shaped gun trigger. When the gun user repeatedly squeezes the trigger, the gun should continue to fire paint balls as rapidly as possible. Guns may be manually loaded before each shot, but most are either semi-automatic, where each time the trigger is pulled a paint ball is fired, or fully automatic, where the balls are fired as quickly as the gun is capable of for as long as the trigger is pulled.
Quite unlike conventional explosive-propelled munitions, current paint balls are relatively round and have an exterior formed from a semi-rigid gelatinous compound. The gelatinous compound is known to be affected by such variables as temperature and relative humidity, and is of course somewhat frangible. During a firing sequence, paint balls on occasion lodge against each other or other objects and block the passageway to the firing chamber, resulting in a jam. While jamming is not new, knowledge from explosive munitions magazines is of little use with the very different paint balls.
Basic paint ball magazines are little more than large hoppers with a feed tube extending therefrom, a sort of closed funnel through which paint balls are dropped into the firing chamber. Unfortunately, the passageway must ultimately taper to isolate single paint balls therein. Usually this is not a gradual taper, but a sudden transition, to reduce the likelihood of two balls getting stuck against each other. Unfortunately, when one paint ball does lodge against the other, the user must shake the gun to free the balls.
One method of preventing paint ball jams is proposed by Miller in U.S. Pat. No. 5,097,816. Therein, a large helical magazine is provided through which the paint balls pass in a single row, eventually leading to the firing chamber. Unfortunately, the Miller design does not use space efficiently, requiring a large helical path with the center portion thereof unused. The extra dimension is undesirable. Furthermore, because of the reduced slope of the surfaces heading into the firing chamber, actual feed rates may be reduced and paint balls may not be provided at speeds sufficient to meet the needs of the more rapidly firing guns. Cleaning of the Miller construction, which is necessary over time to ensure smooth feeding of the paint balls, is difficult also due to the inaccessibility of the central loops of the helix.
Farrell in U.S. Pat. No. 5,511,333 also illustrates a magazine designed not to jam. Unfortunately, the straight tube design severely limits the number of balls contained within a single magazine. When a rapid fire sequence is initiated, the gun may not jam, but it is highly probably that the magazine will empty, still rendering the gun temporarily disabled.
U.S. Pat. No. 5,282,454 to Bell et al, incorporated herein by reference, discloses a large magazine with sloping ends and side walls that lead downward to a tubular passageway referred to as a feed tube. Gravitational forces tend to urge the paint balls to the feed tube, as known in the prior art. The magazine is large, capable of holding many paint balls at a time. The feed tube is connected to the firing chamber of the gun, so that as the paint balls are carried through the tube, they are fed into the firing chamber. Occasionally, a pair of paint balls will simultaneously drop into the opening of the feed tube so that neither can pass, leading to a jam.
To prevent jamming of this type, the Bell et al patent proposes an agitator paddle to stir the paint balls. The agitator paddle may slightly overlap the feed tube opening. In addition to directly clearing any jams at the feed tube opening, the agitator paddle also keeps other paint balls within the magazine moving and available for feeding through the tube. Even if the gun is tilted slightly, the agitator paddle will tend to stir the balls and encourage them to move around, with the increased likelihood that they will continue to pass into the feed tube.
Since the agitator paddle is driven by a small DC motor, batteries are required. Unfortunately, the battery drain is significant. To preserve the battery during periods of non-use, as well as ensure that a user may stay quiet absent the sounds of the motor and agitator, Bell et al disclose an optical sensor within the feed tube which detects an absence of paint balls at a point within the tube. When no ball is present, an electronic circuit triggers the motor to spin the agitator. As soon as a paint ball blocks the optical path, the motor is again stopped.
While the Bell et al design enhances the rate at which paint balls may pass into the feed tube and has enhanced the sport, improved guns and occasional mishaps have revealed limitations therein.
For example, the simple paddle shown in the Bell et al patent, while helpful, still does not ensure sufficient feed rates for newer model guns. To overcome this feed rate limitation, newer designs include higher power motors propelled by twice as many batteries. The standard model agitator is propelled by a single nine volt battery, while the enhanced version is propelled by two nine volt batteries. In addition, the paddle has been redesigned to have four flat surfaces extending longitudinally parallel with the motor shaft and radially therefrom, equidistantly spaced at 90 degree intervals. While this model improves the feed rate significantly, the added weight and cost of the additional battery is certainly undesirable. Furthermore, the added size of the battery compartment makes the gun an easier target for an opponent to hit.
Williams, in U.S. Pat. No. 5,505,188 discloses a coiled tube within the magazine chamber that is pressurized during the firing process to force balls into the feed tube. During rapid fire sequences, the magazine is certainly agitated by motion of the coiled tube. However, the coiled tube does not positively clear the feed tube opening and so can, in some instances, actually create a jam at the feed tube inlet.
Stevens, in U.S. Pat. No. 6,109,252, the contents which are incorporated herein by reference, discloses an improved paint ball carrier which receives paint balls in pockets around the periphery thereof. A guide assembly improves the orderly feeding of balls into an opening.
Anderson, one of the present inventors, in U.S. Pat. Nos. 5,791,325 and 5,947,100 incorporated herein by reference, discloses a paint ball gun including an improved agitator which delivers higher paint ball feed rates than other prior art agitators. Illustrated in those patents are various novel features, combinations, and sub-combinations, the listing herein in summary form not to be interpreted as defining, restricting or limiting the actual contents of those patents, but instead the contents and teachings of these patents are incorporated herein by reference. Such features and combinations are illustrated therein as an electronic circuit having a duration control which delays turning off the motor for a predetermined interval. The motor remains activated continuously during a rapid firing sequence. In addition, a magnetic, sound, pressure, shock or similar sensor is disclosed to trigger the electronic circuit into energizing the motor. The combination of sensor trigger, duration control and agitator design provide a greatly enhanced paint ball gun capable of operating without jamming or undesired noise during non-firing periods. Nevertheless, even further improved magazine paint ball feed rate and more enhanced performance under a variety of conditions are still desired.
In a first manifestation of the invention, a controller for a paint ball gun magazine agitator motor includes a tilt sensor which in response to the magazine being tilted generates an electrical direction indicator signal; a tilt duration detector timing the electrical direction indicator signal; and an electrical circuit for controlling a direction of rotation of the paint ball magazine agitator motor responsive thereto.
In a second manifestation of the invention, a tilt activated relay for powering a paint ball magazine agitator comprises means for detecting tilt of the paint ball magazine with respect to gravity, means for timing a duration of detected tilt, means for determining when the time exceeds a threshold; and means for selectively reversing a rotation of the paint ball magazine agitator motor responsive to the determining means.
In a third manifestation of the invention, a method of refilling a paint ball gun magazine feeder tube comprises the steps of detecting magazine tilt; initiating an electrical pulse responsive to the tilt; and activating a paint ball agitator responsive to the tilt and a demand for paint balls, to thereby move paint balls into the feeder tube.
While the prior art Anderson developments advanced the state of the art, the inventors have discovered that the magazines of the art are sensitive to gun tilt away from vertical, and that this sensitivity can be used advantageously to control paint ball feeding. Exemplary embodiments of the present invention solve inadequacies of the prior art by providing a tilt sensor and control system to change the rotational direction of the agitator responsive to sensed tilt. Additional combinations of magazine and agitator design further benefit the paint ball delivery system.
A first object of the invention is to improve magazine paint ball feed rate. A second object of the invention is to enhance magazine performance under the diverse conditions of a competition or field use. Another object of the present invention is to provide a retro-fit capability to existing guns, to allow upgrade of existing equipment. Yet a further object of the invention is to enable a jammed gun to be reversed, to thereby free the agitator for further use.